As is well known to those skilled in the art, lubricating oils must be characterized by resistance to oxidation, by freedom from haze, and by rust inhibition. Since the oils used as lubricants in the crankcase of large, slow-speed, marine diesel engines are subject to unique conditions of operation, special attention must be directed to the potential problems which are to be encountered. These oils are typically formulated to contain anti-wear additives, oxidation inhibitors, demulsifying agents, rust-inhibitors, etc. Illustrative oils may include those of U.S. Pat. No. 4,358,386 or U.S. Pat. No. 4,375,418 inter alia.
It is found however, that prior art marine diesel crankcase oils are frequently characterized by haze problems caused by the presence of the rust inhibitor component. This is undesirable because it masks or interferes with determination of the presence in the oil of undesirable components including decomposition products, water, or solid particles.
It is an object of this invention to provide a novel crankcase lubricant. It is another object to provide a novel lubricant composition, suitable for use in slow speed marine diesel engine, characterized by its rust inhibition and haze-free properties. Other objects will be apparent to those skilled in the art.